Directional drilling device



May' 31, 1938.

c. N BRUMMETT 2,119,095

DIRECTIONAL DRILLING DEVICE Filed March 4,1937 2 Sheets-Sheet 1 Char/es N. Brummeff 2 Sheets-Sheet 2 mya QwwW

Charles/V. Brummeff May 31, 1938. c. N. BRUMMETT DIRECTIONAL DRILLING DEVICE Filed March 4, 1937 VIII Patented May 31, 1938 UNITED STATES PATENT OFFICE 11 Claims.

This invention relates to new and useful improvements in directional drilling devices.

One object of the invention is to provide an improved drilling device for accurately control- 5 ling the drilling of a well bore.

An important object of the invention is to provide an improved drilling device having a drill bit of any construction mounted on its lower end, the device being so constructed that the bit is suspended in axial alinement with the drill stem while being lowered into the hole and is then inclined to drill in a desired direction upon reaching the bottom of the hole, such arrangement permitting the size of the bit to be substantially equal to the size of the bore, thereby eliminating ofisets or shoulders in thebore upon change of direction in drilling.

Another object of the invention is to provide an improved directional drilling device adapted to be suspended from a drill stem and having a drill bit mounted to undergo an inclination with relation to the axis of the drill stem, whereby the direction of the drilling may be varied; there being means for holding the lower end of the drill stem above the drill bit in axial alinement with the well bore at all times, whereby the bending or bowing of the drill stem, due to the change of direction of drilling is reduced to a minimum and twist-offs are substantially obviated.

A further object of the invention is to provide an improved device of the character described wherein expansible guide members are provided not only for centering the device in the well bore but also for guiding the same in its vertical movement through said bore.

Still another object of the invention is to provide an improved drilling device of the charac-' ter described, including a minimum number of parts which are so connected together that as- 40 sembly or disassembly of the device is readily accomplished; the diameter of the device being such that when connected in the drill stem, the

overhang or protuberance thereof is held at a 45 minimum so that the device may readily be inserted into or removed from the well bore without hanging up, or in any otherway interfering with the running in of the drill stem and bit.

A construction designed to carry out the invention will be hereinafter described, together with other features of the invention.

The invention will be 'more readily understood from a reading of the following specification and by reference to the accompanying drawings, in

which an example of the invention is shown, and I wherein:

Figure 1 is a view, partly in elevation and partly in section of a directional drilling device, constructed in accordance with the invention;

Figure 2 isa horizontal, cross-sectional view, taken on the line 2-2 of Figure 1;

Figure 3 is a horizontal, cross-sectional view, taken on the line 3-3 of Figure 1;

Figure 4 is a horizontal, cross-sectional view, taken on the line 4-4 of Figure 1;

Figure '5 is a horizontal, cross-sectional view, taken on the line 5-5 of Figure 1;

Figure 6 is an enlarged view, partly in section andpartly in elevation showing the connection between the lower end 01' the sleeve and the sub;

Figure '7 is an enlarged view showing one of the expansible alining members; and

Figure 8 is an elevation, showing the device within the well bore in drilling position.

In the drawings, the numeral l designates an elongate, tubular mandrel or body which has an integral collar II at its upper end. The collar is internally screw-threaded to provide a socket l2, whereby the lower end of adrill stem (not shown) may be attached thereto to suspend the mandrel therefrom. The lower end of the mandrel is reduced to form a shank l3 and this reduction in diameter forms an external annular shoulder I on the mandrel. The lower exterior surface of the shank has a plurality of vertically extending recesses or grooves l therein, and although four of these recesses have been shown spaced equally around the shank Figure 4), any desired number may be provided.

For rotatably connecting a drill bit l6 from the lower end of the shank, an annular sub I! has a threaded socket IS in its lower end. The screwthreaded nipple IQ of the bit body is screwed into the socket to connect the sub and bit body together, whereby rotation of the sub imparts rotation to the bit. The bore ii of the sub is of The lower end of the-shank 2! of the sub l1, these slots receive transverse keys 24 which extend upwardly from the internal shoulder 20 of said sub (Figure 5). For suspending the sub from the shank i3, radially extend- "ing pins 25 are threaded in the collar of said normally the pins 25 are resting at the bottom 5 of the recesses, being held so by the weight of the bit and sub. At such time, there is a clearance between the upper end of the keys and the base of the slots (Figure 1) whereby the .shank and sub may undergo a limited movement with relation to each other. During such movement, the pins 25 of course, would move upwardly in the recesses IS. The pins cannot only undergo a vertical movement within the recesses, but are also capable of a limited lateral movement due to the clearance between each pin and the walls of its recess (Figure 4:).

When the mandrel I is attached to a drill stem (not shown) and lowered into the well bore, the weight of the drill bit l6 and sub l1 will cause said bit to hang straight in the bore, as the pins 25 are at such timeresting at the bottom of the recesses. However, when the bit strikes bottom and pressure is applied to one side of the collar at the upper end of the sub I1, said sub and bit attached thereto will be inclined out of axial alinement with the mandrel III. This inclination will be produced by the swinging motion imparted to the sub by the application of pressure to one side of its upper end.

For inclining the bit "5 and sub l1 so as to change the direction of the well bore, a sleeve 26 surrounds the shank [3 of the mandrel i0 being slidably and rotatably mounted thereon. The sleeve has an annular skirt or apron 21 at its lower end and this skirt has its bottom disposed at an inclination (Figure 7) whereby it is highei on one side than on the other.

The upper end of the collar 2| of the sub I1 is formed with an external shoulder 28 whereby its extreme upper end is reduced. The skirt 21 of the sleeve'encircles this reduced upper end and one side of said skirt engages the shoulder, while the other side thereof is spaced from said shoulder.

An internal shoulder 29 is formed between the skirt 2'! and the bore 26' of the sleeve and this shoulder is inclined in a horizontal plane, com plementary to the inclination of. the bottom of the skirt. An annular groove 20 is provided in the shoulder 29 and ball bearings 3| are mounted within this groove and also within a ball bearing raceway in the top of a ring 32 located within the skirt. The ring rests on a metallic ring 33 which is supported on an elastic packing collar 34 disposed within the annular space 22 between the shank l3 and the collar 2| of the sub i1. The-packing collar is, in turn, supported on a g'econd metallic ring 33 which rests on the pins side of the skirt 21 of the sleeve 26 is resting on the shoulder 28 of the collar 2| of the/sub, while the opposite side is spaced therefrom due to the inclination in a horizontal plane of the bottom 01' the skirt. The'weight of the sleeve has caused the packing collar 34 to be deform d M p k g position at one side, while the opposite side of said collar remains in a normal undistorted position (Figure 6). The inherent or natural elasticity of the packing collar, holds the raceway 32 of the bearing 3| in the position shown in Figure 6. At this time, the sub and bit are hanging axially from the shank being suspended from the pins 25.

With the lower end of the sleeve in the position just described, the upper end of said sleeve terminates below a ball bearing raceway ring 35 which surrounds the shank l3 below the shoulder Hi. The ring 35 is slidable on the shank and ball bearings 36 are confined between said ring and an annular groove formed in the shoulder. The ring is formed with an upwardly directed annular flange 35' which is disposed within an annular recess or offset 31 in the exterior surface of the mandrel above the shoulder Id.

The sleeve is provided with a plurality of slots or openings 36 which extend substantially throughout the length of the sleeve. An expansible alining and guide member 39 is mounted in each slot and is arranged to be expanded into engagement with the wall of the well bore. Each member 39 comprises an upper link 40 and a lower link 4! which have their inner ends pivoted together on a pin 42. The upper end of the upper link 40 is pivoted to the sleeve 26 on a pin 43, while the lower link 4| is pivoted thereto on a pin 44. This lower link has a slot 45 through which the pin 44 extends, whereby the sleeve may undergo a limited movement with relation to the link. Three expanding members 39, equally spaced around the sleeve, are shown but obviously, more or less may be employed. A leaf spring 39' is attached to each member "and exerts its pressure to normally hold in the member in its unexpanded position.

When the links are in their normal unexpanded position, the upper end of the upper link extends above the sleeve 26 and engages the raceway ring 35 to hold said ring in engagement with the ball bearings 36. This upper end is curved as shown at 36a, whereby a contact surface is provided. One of the alining and guide members 39 has its upper link providedwith a vertical key 46 which is adapted to engage a complementary groove or keyway 41 in the surface of the shank l2. This groove is located above that portion of the skirt 21 which engages the shoulder 26 which places it diametrically opposite the greatest space or clearance between said skirt and shoulder. When the members 39 are retracted this key engages the groove to lock the sleeve against rotation on the shank. 01' course, when the members are expanded the shank may rotate within the sleeve. 7

In operation,- the'device is lowered into the well bore with the bit inaxial alinement with the 'mandrel and shank. The parts are in the position shown in Figures 1 andr-G, with the pins 26 in the lower ends of the slots, l6 and, a clearance between one side of the skirt 21 and the shoulder 26 of the collar 2] The members 39 are of course in their retracted position at this time.

when the drill bit l6 strikes the bottom of the hole, its movement, as well as the movement of .the sub, is halted. The drill stem and mandrel are continued downwardly so that the keys 24 on the sub l1 move upwardly into engagement with the base oi! the slots 22 and the pins 26 move upwardly within the recesses l6. Since the skirt 21 of the sleeve 26 is engaging the shoulder 28 on the upper end oi. the subcollar at one point there- 2,119,096 on, the sleeve is held stationary along with the moved outwardly to the position shown in dotted lines in Figures 1 and '7. The outward movement of the members 39 causes them to move into engagement with the wall of the well bore. Since 5 the members are spaced equallyaround the sleeve sleeve.

and also since they expand simultaneously, it will be obvious that they act to center the sleeve and mandrel extending therethrough axially within the well bore.

At the same time that the weight of the mandrel and drill stem (not shown) is applied to' the members 38 to move them to their expanded position, this weight is also applied .to the sleeve through the pin 43, whereby said sleeve is tending to move downwardly on the shank. However, since the sleeve is supported at the point A on the shoulder 28, the weight is transferred -to this point at the upper end of the sub. As the expansible members 39 move to their expanded positions, the entire weight of the drill stem and mandrel is then placed on the sleeve as the raceway 35 engages the top of the sleeve. When this occurs, the entire load is placed on the point A at the upper end of the sub and since the sleeve 26 cannot change its position on the shank i3, this load causes the sub i1 and bit to swing laterally so that the upper end of the sub collar 2! contacts the lower end of the skirt throughout its entire periphery. This swinging oi the bit moves the same out of axial alinement with the mandrel and drill stem and therefore, rotation causes the drilling to continue in a direction at an angle to the wellbore (Figure 8).

'The angle of drilling is controlled by the inclination of the bit with relation to the mandrel and this inclination is readily controlled by the inclining of the bottom of the skirt 2] of the It is the clearance between the high side of this skirt and the shoulder 28 which limits the swinging of the bit and sub. When the bit ii moves to its inclined position, the packing collar 3 is deformed or distorted into its sealing position, whereby a fluid tight joint is formed between the shank l3 and mandrel and therefore, drilling fluid may be pumped downwardly through the mandrel and sub to the ,bit.

The drill bit will of course, always incline in a direction away from the point of contact between the skirt 2? and shoulder 28 which is the point A. It is preferable that the groove M be located directlyabove this point or opposite the high side of the skirt. Thus, the expansible member=39 which has the key thereon is always opposite this high side or opposite the direction in which the drill bit will move or swing. Therefore, by noting the radial position of thekey 46 and slot 41, it is possible to lower the device into a well and incline the bit into the desireddirection upon reaching the bottom of the bore.

Manifestly, the members 39, when expanded, act to hold the sleeve, mandrel and drill stem axially alined within the well bore. Therefore,

the drill stem is prevented from bending or bow-v ing excessively which results in more efiicient drilling and obviates danger of twist ofis. The

members 39 not only center the lower end of the" drill stem but also engagein the wall of the bore to provide guides for the vertical movement of the stem through the bore as the drilling continues.

The slot 45 in the lower'end of each lower link M compensates for changes in the formation engaged by the members 39. Assuming the members are engaging a relatively soft formation, they will dig in or engage the formation to a relative- If a hard formation is reached, said members cannot penetrate as deeply and.

1y deep depth.

therefore must be retracted to some degree. This is accomplished automatically for when such a condition arises, the lower" link 40 merely moves downwardly, the pin 44 moving within the slot. Therefore, the expansion .or retraction of the members is possible within certain limits without in any way afiecting the relative positions of the other parts.

From the above, it will be seen that a directional drilling device which is very simple in construction is had. To disassemble the device, it is only necessary to remove the pins 25, and all the parts may be separated. Assembly is just as simple and no adjustments are necessary. Since the device may be lowered into the bore with-the bit suspended axially, the size of the bit may be substantially equal to the size of the bore. When the directional drilling begins, the same size bore is continued at an angle, and the onset or shoulder formed when a smaller bit is employed to change the 'direction of the hole. is eliminated. It is noted that although a fishtail bit is shown connected to the sub ii, any desired type of bit may be employed.

What I claim and desire to secure by Letters Patent is:

1. A drilling device including, a mandrel adapted to be connected toothe lower end ,of a drill stem, a drill bit having driving connection with 2. A drilling device including, a mandrel adapted to be connected to the lower end of a drill stem, a drill bit having driving connection with the mandrel and suspended fromthe lower end thereof and mounted to undergo a limited swinging movement, said bit normally being in axial alinement with the mandrel as the same is lowered through the well bore, means for swinging saidbit to incline the same in a vertical plane when the bit strikes bottom, whereby ,the direction of drilling is changed and means'for centering the lower end of the mandrel and drill stem axially within the well bore when the bit is in its inclined position.

3. A drilling device including, a mandrel adapt- .ed to be connected to the .lower end of a drill stem, a drill bit having driving connection with the mandrel and suspended from the lower end thereof and mounted to undergo a limited swinging movement, said bit normallybing in axial alinement with the mandrel as the same is lowered through the well bore, means for swinging said bit to incline the same in a vertical plane when the bit strikes bottom, whereby the direction of drilling is changed, expansible centering and guiding members mounted on the mandrel, and means for expanding said members into engagement j with the wall of the well bore when the bit is inclined, whereby the lower end of the drill stem is axially alined in the bore and is also guided in its vertical movement as the directional drilling continues. f

4. A drilling device including, a mandrel adapted to be connected to the lower end of a drill stem, a drill bit having driving connection with the mandrel and suspended from the lower end thereof and mounted to undergo a limited swinging movement, said bit normally being in axial alinement with the mandrel as the same is lowered through the well bore, expansible means for centering the lower end of the mandrel and drill stem, and means for imposing the weight of the drill stem and mandrel on the expansible means and also onto one side of the upper end of the drill bit, whereby the centering means is expanded into engagement with the wall of the well bore and the bit is inclined out of axial alinement with the drill stem and mandrel.

5. A drilling device including, a mandrel adapted to be connected to the lower end of a drill stem, a drill bit having driving connection with the mandrel and suspended from the lower end thereof and being capable of a limited swinging movement .with relation thereto, said bit normally being in alinement with the mandrel as the same is lowered through the well bore, a sleeve rotatably mounted on the mandrel above the bit and having its lower end inclined in a horizontal plane, whereby said ,lower end engages the upper end of the bit at only one point on its periphery, and means for imposing the weight of the drill stem on the sleeve, whereby said weight is transferred to the bit at the point of contact of said sleeve, thereby swinging said bit to incline the same in a vertical plane when said bit strikes bottom, such inclination of the bit changing the direction of drilling.

6. A drilling device including, a mandrel adapt-- ed to be connected to the lower end of a drill stem, a drill bit having driving connection with the mandrel and suspended from the lower end thereof and mounted to undergo a limited swinging movement, said bit normally being in axial alinement with the mandrel as the same is lowered through the well bore, means for swinging said bit to incline the same in a vertical plane when the bit strikes bottom, whereby the direction of drilling is changed, and means for controlling the direction in which the bit is inclined to control the direction of drilling.

7. A drilling device including, a mandrel adapted to be connected to the lower end of a drill stem, a drill bit having driving connection with the mandrel and suspended from the lower end thereof and mounted to undergo a limited swinging movement, said bit normally being in axial alinment with the mandrel as the same is lowered through the well bore, means for swinging said bit to incline the same in a vertical plane when the bit strikes bottom, whereby the direction of drilling is changed, means for controlling the-direction in which the bit is inclined to control the direction of drilling, and means for centering the lower end of the mandrel and drill stem axially within the well bore when the bit is in its inclined position.

a. A'drilling device including, a mandrel adapted to be connected to the lower end of a drill stem, a the mandrel and suspended from'the lower end drili bit having driving connection with thereof and being capable of a limited swinging movement with relation thereto, said bit normally being in alinement with the mandrel as the same is lowered through the well bore, a sleeve rotatably mounted on the mandrel above the bit and having its lower end inclined in a horizontal plane,

whereby said lower end engages the upper end of the bit at only one point on its periphery, means for imposing the weight of the drill stem on the sleeve, whereby said weight is transferred to the bit at the point of contact oi. said sleeve, thereby swinging said bit to incline the same in a vertical plane when said bit strikes bottom, such inclination of the bit changing the direction of drilling, and means for controlling the direction in which the bit, is inclined to control the direction of drilling.

9. A drilling device including, a mandrel adapted to be connected to the lower end oi a drill stem, a drill bit having driving connection normally being in alinement with the mandrel as the same is lowered through the well bore, a sleeve rotatably mounted on the mandrel above the bit and having its lower end inclined in a horizontal plane, whereby said lower and engages the upper end of the bit at only one point on its periphery, means for imposing the weight of the drill-stem on the sleeve, whereby said weight is transferred to the bit at the point of contact of said sleeve, thereby swinging said bit to incline the same in a vertical plane when said bit strikes bottom, such inclination of the bit changing the direction of drilling, and means for centering the lower end of the mandrel and drill stem axially within the well bore when the bit is in its inclined position.

10. A drilling device including, a mandrel adapted to be connected to the lower end of a drill stem, a drill bit having driving connection with the mandrel and suspended from the lower end thereof and being capable of a limited swinging movement with relation thereto, said bit nor- I mally being in alinement with the mandrel as the same is lowered through the well bore, a sleeve rotatably mounted on the mandrel, above the bit and having its lower end inclined in a horizontal plane, whereby said lower end enses the upper end of the bit at'only one point on its periphery, means for imposing the weight of the drill stem on the sleeve, whereby said weight is transferred to the bit at the point oi contact of said sleeve, thereby swinging said bit to incline the same in a vertical plane when said bit strikes bottom, such inclination of the bit changing the direction of drilling, and expansible centering and guiding members mounted on the sleeve and arranged to be expanded by the weight of the drill stem, whereby the lower end of the drill stem is axially alined in the bore and is also guided in its vertical movement as the directional drilling continues.

11.- A drilling device including, a mandrel adapted to be'connected to the lower end of a drill stem, a drill bit having driving connection with the mandrel and suspended from the lower end thereof and being capable of a limited swinging movement with relation thereto, said bit normally being in alinement with the mandrel as the same is lowered through the-well bore, a sleeve rotatably mounted on the mandrel above the bit and having its lower end inclined in a horizontal plane, whereby said lower end engages the upper end of the bit at only one point on its periphery,

means for imposing the weight of the drill stem on the sleeve, whereby said weight is transferred to the bit at the point of contact of said sleeve,

thereby swinging said bit to incline the same in holding the members in their retracted position,

and means for imposing the/weight of thedrill stem on said members to expand the same into engagement with the wall of the well bore, whereby the lower end of the drill stem is axially alined in the bore and is also guided in its vertical movement as the drilling continues.

CHARLES N. BRU'MME'I'I. 

